Xl and fxp driver polling support and rx/tx offloading

i checked on a search on the forum and someone stated that when polling is enabled i should see it on options = on ifconfig and i already searched and is sure both fxp and xl drivers support polling on freebsd. i wonder why i cant enable it on my system. and i just wanna ask which is a better nic. the fxp or xl ? i can see in options = that xl drivers does rx offloading. but fxp doesnt. any comments are welcome